The Vegetarian Resource Group Blog

Information About L-cysteine

Posted on April 22, 2013 by The VRG Blog Editor

By Jeanne Yacoubou, MS
VRG Research Director

A journalist recently asked us about L-cysteine for an article she was doing on food additives. For others interested in L-cysteine, here’s a summary in question and answer format based on information relayed to us by several food industry employees over the past few years.

Q. Is L-cysteine a softening agent that is used in many types of bread?

A. L-cysteine is best described, (as it is in the FDA’s Code of Federal Regulations), as a dough conditioner or dough strengthener. It makes the dough more manageable, (i.e., able to be stretched out and unlikely to bounce back to its original ball-like state when making a pizza crust, for example).

It is most common in pizza dough and bagels. It may be present in other types of bread products, too.

Q. Can it be derived from hog hair, human hair, and feathers?

A. The major commercial sources of L-cysteine today are Chinese and Indian avian feathers and human hair. Hog’s hair as a source is likely when the hair/feather supply is low. Because the industrial plants needed to extract L-cysteine exist in China, most of the extraction is done there (i.e., it’s too costly for companies to ship feathers/hair and extract it here when the feathers, hair and industrial plants are already there).

Dark hair is richer in L-cysteine than light hair. Although there is no technical difference between L-cysteine derived from feathers versus that derived from human hair, industry sources have told us that human hair-derived L-cysteine is considered better and preferred in Europe.

Q. Is it sometimes, but not always, listed on labels?

A. According to the CFR ( under paragraph 18, L-cysteine is listed on labels, usually in a parenthetical expression after the term “dough conditioner.” However, it need not be listed if L-cysteine is an ingredient used to make other ingredients which are in a final product. For example, L-cysteine used as a “reaction flavor” ( see #7) need not be labeled. Another example is in a pizza kit in which there are individual packets of dough, sauce, and seasonings in a larger box. L-cysteine may be in the dough but not labeled as an ingredient in the kit.

Q. Is it safe (but possibly undesirable) to eat?

A. L-cysteine has GRAS status (Generally Recognized as Safe)

FDA considers it safe when used at suggested levels for dough conditioning. Human or animal sources may be undesirable to some people. Synthetic and microbial versions of L-cysteine exist and are used in products with an approximately 10% total market share, but at present are more costly than hair- or feather-derived L-cysteine.

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The contents of this article, our website, and our other publications, including the Vegetarian Journal, are not intended to provide personal medical advice. Medical advice should be obtained from a qualified health professional. We often depend on product and ingredient information from company employees or company statements. Information changes and mistakes are always possible. Please use your own best judgment about whether a product is suitable for you. Further research or confirmation may be warranted.

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6 to “Information About L-cysteine”

  1. Melanie says:

    Using human hair extract to condition dough. Now my friends are going to call me a conspiracy theorist. Pretty gross, when you think about it.

  2. Sarah says:

    I am surprised this hasn’t become more mainstream in gross food news. Human Hair? Where do they gather this human hair? Are they harvesting it in some specific way? So strange.

  3. Mark Z. says:

    Sarah, the human hair is from the floor sweepings of India and China barber shops and hair salons, so it is a cheap, easily replenished source. I’m sure they boil/clean it, if that means anything.

    Dunkin Donuts used this hair derived version for certain products in the 1980’s, but since Halal groups complained it was considered canabalism to eat human parts, they were force to switch to bird feathers, erm, pardon me, “avian sources”.

    New topic. Anything which is “synthetic” is still made from raw ingredients which are either animal, mineral, or vegetable. There is no law that the raw materials used must be vegetarian/vegan. Heck, since no animals were killed, I guess some might even consider l-cysteine derived from human hair to be vegetarian, just as animal derived egg shells are, but not vegan. Anyone know more?

  4. Richard says:

    Just wanted to say it cannot be sourced from human hair in the European Union (see page 255)

    Nothing disgusting about L-cysteine, it’s a ‘natural’ food additive!

  5. Dan says:

    Giardia thrive on l-cysteine, best to avoid it when trying to overcome giardiasis.

  6. Dr. Neil Ross says:

    Write your Congressional representative. Also, I’m sure it isn’t considered Kosher by the Jewish Orthodox Union.

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